Flash-light powder.



which were hitherto necessary.

- or tablets or pressed into strings. In selectif'ery especial photochemical properties.

'are made in sucha'waythatthey not only;

' have been foun'dto be absolutely permanent when mixed withothe'rs, namely powderedsilicates, suchfor instance as. glass powder,-

respective color.- These mixtures may "beburnedeither.inthe form of powder loosely after ashort time.

found thatthe fluorid's are suitable as flame UNITED sTA'rEs rarenrorrrcn GOTTLIEB KREBS, or oFFiiNBAOH-ON-M IN, GERMANY.

FLASH-LIGHT POWDER.

I The improved light producing compounds are of unlimited permanency, but also give off but very-little smokeless and entirely non-poisonous, gases. v

,The important feature in this invention consists in enabling colored exposures to be made with theseiimproved composite powsuitabl'e'color may, be reproduced in i'ts' c or"ect color yalue'without necessitating the use of thellight 'filtersf In these improved light producing'c( mpounds, such substances, are employed which and dehydrated chrome alum, alsov dehydrated sulfates-of copper, and finally the sulfates of the rare earths andnietallic sult'ates. These substances, in order to be able to exactlyhegulatc their period of combustion, are-mixed with suitable quantities of oxide, protoxidsfor carbonates of 'the' rare or alkaline earths and metals, also with or sugar, flourpdextrin and like substances, in such a way that by means of these add trons combustion isretarded' as much as 1s.

necessary-tor a flame coloring action of the scattered about, or in the form'of cartridges ing the flamecoloringsubstances,care mustbe taken that they do notchemically decoin-- pose when brought into contact with the constituents of the respective,powdermixture, assuch mixture would cease to flame Such additions must alsocontain no poisonous gases orproduce much smoke, and must not be explosive, as ptherwise. the techn cal advantages are 1l1 u sory. After many experiments, it has been coloring -substancesif they fulfil all the- Specification of Letters Patent.

,.Application filed October 20, 1905. Seria1 No. 283,6-18.

photography, there is taken Patented Apri1 20, 19"09.

conditions hereinbefore' s'et fort-h-.. Thus for instance for yellow and-orange light filters iiuorld of sodium and fluorid of ea'lcium'are employed. For blue filters,':fiuorid Of COP -f per, for green filters fluorid of barium. and

for. red filters "fiuorid of lithiiun. Other flame coloring substances may however be employed, such for instance as 'zi'nc dusb.-

copper bronze, caesium, .rubidum, thallium, indiumv and likesalts, more particularly-also the organic compounds-of all these flame coloring substances.

-Exani 'ile's; F orimaking colored time-light cartr1dges,'-which" serve both as artificial so rce or light'"an'd as a substitute for a co'l on filter, in photography with sensitive plates, filaments or papersin the tlnreecolor A. As a substitute-for yellow or orange filters; .'2.-grains of aluminum powder, 2- grams of magnesium powdery} 2 grams of.

SugargflOA grain of'flu'orid of sodium.

:B. Asa substitute for blue light filters 2 grains of magnesiun'i powder, 2 'grains'ot alui'ninum powder, 2 grainsjof sugar, 0.3 grain of zincdust. I

'O. Asa substitute for green light jfil-p ters-;2 grains of alhminunr powder, 2.

grams magnesium powder, 2 grainsjcerium carbonate, 0.4:gra1n fiuorid of barium.

D; a substitute for red light filters ;-'2

grains of aluminum powder, 2 grains of magnesium powder, 1' gram thorium sulfate,.

1 grain, of oxid of ceriun'u, 0.3- grain-of fluor-id oi." lilitium, grain of oxidfot lithium. Y

' In all these examples the mixtures ofthe placed by similar mixtures;v All the pow-- and burned v I claim as mymvent onz- A- 'compositionffojr. producing colored. light, consisting: offtwo :parts of alun'nnum' powder, two parts of. 1nagnes1um powder,"

two partsofsuga-r, -and four tenths part oitluorid of sodium.- f I In witness whereof, I have hereunto signed my name t-l1is'27th day of Sep'ten1-- ber 1905, in the presence of two subscribing witnesses. v

I GOTTLIEB KR-EBS.

\Vitnesses: JEAN GRUN Qaa'r, GRUND.

powders 'niay be -1 1'1utually' exchanged or re? '95- .(lers mayfinally be -mixed ivith one another 

